The present invention relates to a ladder stabilizer for an extension ladder.
U.S. Pat. No. 4,899,849 (Levi et al) discloses a ladder stabilizer that has two stabilizing legs and two braces. Each of the stabilizing legs and each of the braces are pivotally secured to a ladder by means of a bracket. The bracket is fastened to opposed side rails of the ladder by bolts which are inserted through apertures drilled through the side rails.
While ladder stabilizers, such as those disclosed by Levi et al, appear to greatly enhance the stability of a ladder, they all have one basic problem. The laws of many legal jurisdictions require that ladders be certified by qualified engineers as being capable of supporting anticipated loads. Apertures drilled through the side rails of a ladder void such certification, due to the fact that such apertures may adversely affect the ladder""s load bearing capability.
What is required is an alternative configuration of ladder stabilizer that is securable to a ladder without drilling apertures through the ladder.
According to the present invention there is provided a ladder stabilizer which includes a substantially planar rigid frame having two legs depending in spaced apart relation with a fixed angular relationship to the frame. The frame has a first end and a second end, with remote ends of the two legs defining the second end. A pivot bar is provided, together with means for securing the pivot bar to a selected rung of a ladder. Pivot bar retention brackets are secured to the frame in spaced relation adjacent to the first end. Means is provided for limiting pivotal movement of the frame about the pivot bar.
With the ladder stabilizer, as described above, the legs of the stabilizer are rigidly fixed to and form part of a frame, with the frame pivoting about a pivot bar that extends through one of the hollow rungs of the ladder. This enables the ladder stabilizer to be secured in position, without drilling apertures through the ladder. As the ladder has a plurality of rungs along its length, the ladder stabilizer can be adapted to accommodate stairs, and other demanding applications by varying the rung through which the pivot bar extends.
There are various means that can be used to limit the pivotable movement of the frame about the pivot bar to prevent an unintended collapse of the legs. In the preferred embodiment, which will hereinafter be further described, two limiting means are used. A first means for limiting pivotal movement of the frame about the pivot bar is a line extending from each of the remote ends of the legs, which is securable to the ladder. A second means for limiting pivotable movement of the frame about the pivot bar is a pivotal stop extending from the frame and adapted to engage the ladder upon pivotal movement of the frame.
Although beneficial results may be obtained through the use of the ladder stabilizer, as described above, if the pivot bar were to become displaced, the ladder stabilizer could collapse. Even more beneficial results may, therefore, be obtained, when a line extends from each end of the pivot bar, which is securable to the ladder to limit axial movement of the pivot bar.